226. What are the various strengths of common grades of magnet material? Kathy Shick, Bloomington, Indiana
I get many questions about magnets and suppliers. I had a shorter version of this chart in the previous issue of Vintage Guitar Magazine and this chart that gives you the Magnet Material, Nominal Chemical Composition, Gauss, Oersteds and Maximum Energy.
Magnet material
Nominal Chemical Composition
Gauss
Oersteds Nominal
Maxim-um Energy
3.5% Cr Steel 3.5 Cr, 1 C, Bal. Fe 10300 60 0.30
3% Co Steel 3.25 Co, 4 Cr, 1 C, Bal. Fe 9700 80 0.38
17% Co Steel 18.5 Co, 3.75 Cr, 5 W, .75 C, Bal. Fe 10700 160 0.69
36% Co Steel 38 Co, 3.8 Cr, 5 W, .75 C, Bal. Fe 10400 230 0.98
Alnico 1 12 Al, 21 Ni, 5 Co, 3 Cu, Bal. Fe 7200 470 1.40
Alnico 2 10 Al, 19 Ni, 13 Co, 3 Cu, Bal. Fe 7500 560 1.70
Alnico 3 12 Al, 25 Ni, 3 Cu, Bal. Fe 7000 480 1.35
Alnico 4 12 Al, 27 Ni, 5 Co, Bal. Fe 5600 720 1.35
Alnico 5 8 Al, 14 Ni, 24 Co, 3 Cu, Bal. Fe 12800 640 5.50
Alnico 5DG 8 Al, 14 Ni, 24 Co, 3 Cu, Bal. Fe 13300 670 6.50
Alnico 5 col. 8 Al, 14 Ni, 24 Co, 3 Cu, Bal. Fe 13500 740 7.55
Alnico 6 8 Al, 16 Ni, 24 Co, 3 Cu, 1 Ti, Bal. Fe 10500 780 3.90
Alnico 8 7 Al, 15 Ni, 35 Co, 4 Cu, 5 Ti, Bal. Fe 8200 1650 5.30
Alnico 8 HC 8 Al, 14 Ni, 38 Co, 3 Cu, 8 Ti, Bal. Fe 7200 1900 5.00
Alnico 9 7 Al, 15 Ni, 35 Co, 4 Cu, 5 Ti, Bal. Fe 10500 1500 9.00
Sint. Alnico 2 10 Al, 19 Ni, 13 Co, 3 Cu, Bal. Fe 7100 550 1.50
Sint. Alnico 5 8 Al, 14 Ni, 24 Co, 3 Cu, Bal. Fe 10900 620 3.95
Sint. Alnico 6 8 Al, 16 Ni, 24 Co, 3 Cu, 1 Ti, Bal. Fe 9400 790 2.95
Sint. Alnico 8 7 Al, 15 Ni, 35 Co, 4 Cu, 5 Ti, Bal. Fe 7400 1500 4.00
Sint. Alnico 8 HC 7 Al, 14 Ni, 38 Co, 3 Cu, 8 Ti, Bal. Fe 6700 1800 4.50
Ceramic 1 MO.6 Fe2O3 2300 1860/3250 1.05
Ceramic 2 MO.6 Fe2O3 M represents one or more of the 2900 2400/3000 1.80
Ceramic 3 MO.6 Fe2O3 metals chosen from the group Barium, 3300 2200/2400 2.60
Ceramic 4 MO.6 Fe2O3 Strontium, Lead 2500 2300/3800 1.45
Ceramic 5 MO.6 Fe2O3 3800 2400 3.40
Ceramic 6 MO.6 Fe2O3 3200 2820/3300 2.45
Ceramic 7 MO.6 Fe2O3 3400 3250/4000 2.75
Ceramic 8 MO.6 Fe2O3 3850 2950/3050 3.50
Cunife 1 60 Cu, 20 Ni, 20 Fe 5500 530 1.40
Vicalloy 1 10 V, 52 Co, Bal. Fe 7500 250 0.80
Remalloy 12 Co, 15 Mo, Bal. Fe 9700 250 1.00
Rare Earth Cobalt 12 Re-Co RE represents one or more of the metals 7200 6500/10000 12.00
Rare Earth Cobalt 15 Re-Co chosen from the rare earth group: Samarium, 8000 7000/14000 15.00
Rare Earth Cobalt 16 Re-Co Praseodymium, Cerium, Yttrium, Misch Metal 8300 7500/18000 16.00
Rare Earth Cobalt 18 Re-Co 8700 8000/20000 18.00
Symbol & Name
Al = Aluminum Mo = Molybdenum
C = Carbon Ni = Nickel
Co = Cobalt Pb = Lead
Cr = Chromium Ti = Titanium
Cu = Copper V = Vanadium
Fe = Iron W = Tungsten
Magnets with the nominal specifications can have minimal and maximum combination of material to make the magnet rod or bar used in various pickups. This accounts for magnets that are stronger than others even with the same grade of material. Magnets with a balance of (Fe) or Iron can explain why the magnets rust and the cause for ICPC (Inner coil pole corrosion) discussed in earlier issues of Vintage Guitar Magazine. The symbols and name are from Periodic Table and show the chemical composition for each grade of magnet.
227. Can flatwork be routed or punched out for making bobbins? Len Burt-Gibbstown, New Jersey
Depending on your material used for making flatwork, routing, punching, machining and fabricating can be done. Using laminates such as paper phenolic, cloth or glass-reinforced will determine which type of fabrication can be done. Most machining operations common to metal can be done to paper and cloth re-inforced laminates. Punching laminated parts is called blanking, piercing, shaving or a combination of the operations with a suitable die mounted to a punch press. NEMA (National Electrical Manufacturers Association) designate punchability of paper base laminates by the letter “P” appearing in the grade number. Phenolic grades such as XP, XXP, XXP or PC are best suited for punching as is Vulcanized fibre. Canvas, linen-base or glass-base laminates are not designated for punching but some pickup manufacturers do it anyway. The edges tear or pull out making the bobbin look bad and bobbin windability is not always great.
Some laminates are hot punched and cold punched. If you punch out laminate material it is important to increase punch side for standard tolerance. Depending on the size of your flatwork the tolerances are as follows for paper and cloth base laminates.
Material Increase punch size Increase punch size
Thickness for standard tolerance for close tolerance
In: In: In:
1/64 .002” .001”
1/32 .003” .002”
3/64 .004” .003”
1/16 .005” .004”
5/64 .007” .005”
3/32 .008” .006”
7/64 .011” .009”
1/8 .012” .010”
When drilling laminates a 70? point should be used for paper and cloth laminates and a 118? point is best for glass reinforced laminates. When counter-sinking pickguards try to use a 82? single fluke countersink bit. Most all oval-head screws used on Fender guitars have a 82? angle on the underside of the screw. This includes neck plates, control plates, Telecaster bridge plate and various pickguards.
228. Can you make a tapped pickup stereo? Jason Banks-Los Angeles, California
You can make your pickup have two different outputs with different frequencies. A tapped pickup can’t give you each string to different channels or amplifier. You would need to have six individual coils for left-right-left etc. A tapped pickup is wound to a desired number of turns or to a desired frequency. The frequency will determine how much bass or treble the pickup will have. Usually less turns on the coil will give you less output but a brighter frequency. The more turns the hotter the output and less treble the pickup will have. Use of preamps and circuits can change the tonal character and output in a pickup. Each tap in a pickup can be sent to a different channel or amplifier and will need to be wired for the right volume and tone controls and stereo jack if using the tapped signal, including full output from the pickup. Capacitors can be used to reduce brightness in a pickup by soldering one side to ground and the other to the hot output. By putting a capacitor in series with the hot output of a pickup will give the pickups a unique tone. This is a circuit I used when working with Jerry Donahue and his signature Telecaster. Using .0033 mfd. capacitor in series with your hot output from your bass pickup will give you a sound similar to a Rickenbacker trademarked by Chris Squire in the group “Yes.”
229. I was trying to hand wind a Fender Stratocaster bobbin using a home made winding machine that consisted of a sewing machine motor and foot pedal for the speed control. When I hand wind the magnet wire on the bobbin the DC resistance is only 2.9 k ohms. I thought it should be around 6.0 k ohms. What is wrong?
There could be several things wrong and first are you sure that the magnet wire is 42 gauge? Sometimes if you buy surplus magnet wire the label might be wrong and that’s why it’s surplus! If the wire is old the insulation might be brittle and flake off as you are winding. This can happen to the older plain enamel or Formvar insulation’s. If you wind the bobbin too fast and have too much tension on the magnet wire the insulation can become exposed and short out to other turns in the coil. There are many reasons why the bobbin reads so low and my first thought was it was the wrong gauge magnet wire. You need to contact a magnet wire supplier and get a magnet wire chart that gives you specifications on each gauge of common magnet wire. I often measure ten feet (10’) and multiply by 100 to get “ohms per 1,000 feet. This will give you a more accurate reading than just measuring the diameter. The bare magnet (copper) wire diameter can have minimal, nominal and maximum tolerances. It can also have the same tolerances for the insulation and build coating the magnet wire. Some insulation’s can have single, double (heavy) or even triple build or thickness of insulation coating the magnet wire. The coating keeps the magnet wire from shorting pre or post turns in a coil. When you wind the Fender style bobbin with 42 plain enamel, Formvar or other Poly insulation with 7800 to 8300 turns you should have a pickup that reads from 5.8k to 6.3k. There are so many variables such as magnet wire diameter, magnet wire resistance, tension, winding tolerances, temperature and winding speed to name a few. Another important factor is the tolerance of the ohm meter you are using. Is it analog or digital and are the batteries good! Do not touch the ends of the meter probes as your fingers can interfere with the results when reading the DC resistance of your pickups.
230. How is the insulation put on the bare copper wire used in winding coils? Tom Watters-Santa Barbara, California
The bare copper wire that is 99.9% pure is run through a series of rollers with a pad saturated in the insulating material such as Plain Enamel or Formvar which is common in most vintage pickups. As the magnet wires passes the saturated pads, the bare copper wire is coated with the desired insulating material. The wet copper wire then passes through heated oven that bake the insulation so it becomes dry and ready for the second or even third coatings of insulation. After the desired thickness of coatings the magnet wire is wound onto spools ready for inspection and shipped to the desired location. A long time manufacturer of magnet wire insulations is Schenectady International which is based out of Schenectady, New York. Product manager Mark A. Belill is in charge of Primary Insulations and the Polymer Division. Schenectady Chemical has been in business for more than 85 years have are the innovators of insulating varnish and magnet wire enamel. Their first products were insulating varnishes and high temperature coatings. They spend much time on research and development working with many companies that draw copper wire into various guages. Their insulations are also used on Aluminum, Silver and Gold magnet wire. Schenectady Chemical has many facilities around the world and offer the widest variety of magnet wire enamels. They can make magnet wire insulations to your specifications. Below are a list of the various types of Magnet Wire Enamel available from Schenectady International.
Magnet Wire Enamel Flash Point General Use
Polyester Insulations
Isonel 155-40 54?C / 129?F General purpose Class F
Isonel 155-Code 12079A-40 41?C / 106?F High cut-thru Class F
Isonel 200-Code 516 51?C / 123?F High performance for rectangular wire
Isonel 200-Code 1125 59?C / 139?F General purpose, high solids
Polyesterimide Insulations
Isomid 43 52?C / 125?F High performance for rectangular wire
Isomid 860-38M 52?C / 125?F High performance, high “imide”
Isomid 1076 45?C / 113?F General purpose
Isomid 1363 48?C / 119?F General purpose
Isoweld 1743 41?C / 105?F Weldable
Isomid 10639 54?C / 129?F For large round wire
Isomid 10982 45?C / 113?F For large round wire
Isomid 11348-40 52?C / 127?F High “imide”
Isomid 11815 52?C / 127?F Medium “imide”
Isomid 11969-40 52?C / 127?F Low “imide”
Polyurethane Insulations
Isomelt 1500 36?C / 96?F General purpose
Isomelt 15001-35 36?C / 96?F General purpose for hotter ovens
Isomelt 1566 34?C / 93?F Fast soldering
Isomelt 1566L 34?C / 93?F Very fast soldering
Isomelt 1700 39?C / 103?F Passes Class F heat test
Isomelt 11022B-36 34?C / 93?F Flexible
Isomelt 11536 39?C / 103?F Passes Class F heat test
Isomelt 12524-40A 34?C / 93?F High solids
Polyvinylformal Insulations
Formvar 1078B 51?C / 123?F General purpose
Formvar 1171K 46?C / 115?F High performance
Formvar 1253T 51?C / 123?F High solids, low viscosity
Formvar 11313C 51?C / 123?F High solids
Polyamideimide Insulations
Amideimide 1647 32?C / 89?F Gen. purpose Al-monolithic application
Amideimide 1924C 46?C / 115?F Gen. purpose Al-monolithic application
Amideimide 10514C 32?C / 89?F High performance-monolithic app.
Bondcoat Insulations
Bondall 16H 44?C / 112?F Heat or solvent activated-130?C service
Bondall 506 41?C / 105?F Epoxy-heat activated 150?C service
Bondall 1539 34?C / 93?F Aromatic polyamide-heat activated
Bondall 1540 34?C / 93?F Single oven operation-heremetic
Nylon Insulations
Nylon 910 47?C / 116?F Modified Nylon 6/6 high solids
Nylon 1882 31?C / 88?F Nylon 6/6
Nylon 1416 39?C / 103?F Nylon 6/6
Nylon 1922 47?C / 116?F Modified Nylon 6/6 high solids
The above information is basic information on various types of insulations available today for most magnet wire applications. Other important information will be supplied in future articles of Vintage Guitar Magazine.
231. What is a passive and active pickup? Randy Collins-Buffalo, New York
Passive pickups used for guitar and bass is in general a musical instrument pickup consisting of a permanent magnet material such as Alnico, Ceramic or other specified material such as Rare Earth. A coil form or bobbin of a certain length, width and height needed to hold the wound coil. Magnet wire can be wound directly around a magnet such as the Dan Electro “Lipstick” tube pickups. Magnet wire can be wound around rod or blade magnets, studs or blades of soft iron or special grades of magnetically conductive stainless steel. Various gauges of magnet wire are wound to a desired number of turns and layers. The desired number of turns per layer are done with a coil machine with an automatic traverse control. Scatter winding hand layers the turns to the winders specific needs. Passive pickups have many wiring and phasing options. Passive pickups use no internal or external pre-amps.
Active pickups consist of a magnet source and material, a coil wound for desired impedance and frequency and pre-amp or booster usually built internally or externally and consisting of a battery or power supply. Active pickups can use various forms of power such as 9 volt, 18 volt etc., similar to condenser microphones that use a 48 volt phantom power supply either by internal batteries, a connecting box or power from the sound board. Active guitar and bass pickups usually have a fixed magnetic polarity facing the strings, fixed internal electrical phasing and lower impedance coils. Most active pickups are potted in a resin that eliminates tampering and repairability if the pickup fails. Both passive and active pickups can have external active tone circuits and pre-amps added but caution must be taken with adding new circuits with existing power supplies.
232. Where can I get battery clips and terminals needed for hooking up active bass pickups. Todd Johnson-Vancouver, Canada
There are many suppliers of components and hardware that can be used when working on your instruments. One of my favorites is a company called Keystone Electronics Corp. Their address is 31-07 20th Road, Astoria, New York 11105-2017 (718-956-8900). You can ask for their catalog or have your local electronics store order a one for you. They can also give you the name of the nearest distributor. The Keystone catalog is great to look at with lots of drawings and specifications useful for repairman and builders. Some of the useful components need for guitar modification and repair are: Alligator Clips, Banana Plugs & Jacks, Battery Holders, Brackets (Mounting), Bushings, Grommets, Cable Clamps, Clips, Connectors, Eyelet’s, Fibre Washers, Fuse Clips & Holders, Handles, Insulating Hardware, Jacks, Lugs, Nuts, Phono Jacks & Plugs, Testing Probes, Screws, Solderless Terminals, Spacers, Standoffs, Tools and many other useful items.
233. Can I put rod magnets in the bobbin where the steel studs are in my humbucking pickup? Brian Nelson-Philadelphia, Pennsylvania
The standard size for a stud on a Gibson humbucker is .187” diameter by 1/2” long. The normal stud polarity is North on a standard humbucker. You would need to keep the magnets as close to length as the steel studs. When you insert the magnet rods, you need to keep the magnetic polarity “North” facing the strings. The steel stud pole pieces are plated to keep from rusting and increases the diameter that keeps the stud firmly held into the plastic molded bobbin. Trying to grind or cut a magnet already magnetized for proper length can cause several problems. Grinding or cutting magnets will cause fine bits of magnetic dust to become airborne that are harmful if inhaled. Grinding can cause the magnet to get overheated and become degaussed or weaker. It would have to be magnetized to bring it back to its proper strength.
234. What makes a similar looking pickup sound different? John Carter-London, England
There are many factors that make similar looking pickups sound different. Here are some ideas:
1. Magnet material:
A. grade
The magnet material comes in several grades and dimensions. Earlier articles in VGM show various grades of magnetic materials
B. supplier
Depending on what supplier the fabricator gets the raw stock before grinding and cutting will determine the quality and standards used in making the magnet.
C. how magnetized
Magnets can be magnetized by several methods: discharge, inductors, impulse and in contact with other magnets.
D. calibration
Depending on the material and amount of ampre turns needed to magnetize the material to full saturation. Using lower ampre turns will not fully align the domains in the magnet and magnetizm will not be fully achieved. Calibration is determining the precise amount of magnetic field needed for a specific application and done with the use of calibrating inductors.
E. age
The age of the material will have an effect on the magnet with natural loss of magnetic gauss or strength.
F. enviormental effects
Heat, shock and electrial interference can de-gauss the strength of a magnetic field within a magnet
G. magnet polarity.
Magnets can have a north or south polarity on either end or specially magnetized for specific magnet designs or shapes.
2. Bobbins specifications:
A. flatwork thickness
Depending on the flawork thickness will do several things. The thicker the top flatwork on a bobin will add strength to support the coil windings but also keeps the coil further away from the strings. Thinner flatwork allows the pickup to be raised closer to the strings especially when covers are used. Thinner top flatwork that has great pressure from the wound coil can lift and warp under hot and humid conditions.
B. pole spacing
The pole spacing can be different from guitars made in Japan, Europe and the USA. Manufactures use different methods of measurement such as metric and English conversions. Pole spacing can be different from Fender spaced, “F” Spaced or Trem spaced and to Gibson Spaced. Bar and blade pole pieces are used to accommodate the various string spacing on guitar and basses.
C. traverse
The traverse is the winding width of the coil or the distance back and forth when the coil is wound. The spacing determines the maximum number of turns of a coil when wound side by side in a given area.
D. pole arrangement
The pole arrangement can be either steel screws to conduct the magnetic field to the strings or rod magnets either flat or staggered. The pole piece can be a blade, steel rod, magnet rod or bar, steel blade or combination of blades or any ferrous material to conduct the magnetic field to the strings.
E. bobbin material.
The bobbin material adds to the stability and shape of the coil form. Molded bobbin are generally more consistent than bobbins with fabricated flatwork. The majority of Fender style flatwork is made from the Vulcanized Fibre which is compressed paper and very vulnerable to moisture and exposure. Plastic based materials used for humbucking bobbins is more durable to long playing as long as styrene plastics are not used for bobbins as it will wear away exposing the coil and possible damage.
3. Winding specifications:
A. magnet wire gauge
Magnet wire comes in a number of gauges and insulation thickness. The normal wires used for guitar and bass pickups are 42, 43, 44. The larger the number or AWG, the bare magnet wire diameter gets thinner. The thinner the bare wire the higher the DC resistance for a given length as compared to 43 which is lower than 44 and 42 which is lower than 43 gauge of magnet wire.
B. bare wire diameter
Magnet wire is drawn to a precise bare diameter dimension before insulation is added. If you wound a coil with uninsulated magnet wire the coil would completely short out across the beginning and finish of the coil. The coil wouldn’t induce an alternating current needed to produce a signal to the amplifier. Magnet wire come in Minimal, Nominal and Maximum outside diameter (OD) before the insulation is put on to the desired thickness or layers.
C. insulation thickness
Insulation is put on in layers and dried in heating ovens. Several layers can be added depending on the build needed for a specific use. If AC or DC current is used than a thicker insulation is used when higher current or heat is a factor. Normally guitar pickups don’t produce heat and thinner insulations can be used allowing more winding room within the bobbin or coil form.
D. ohms per thousand feet
I measure ohms per thousand feet to get a better average on the magnet wire used. I mark all the spools to better keep coils within a specific winding and DC resistance. I measure 10 feet of magnet wire and mutiply it by 100 to give me ohms per 1,000 feet. I have a magnet wire chart and it will tell you what the “American Wire Gauge” (AWG) is. You can determine if it’s closer to a lower gauge or a higher gauge.
E. number of turns
The number of turns does several things. It tells you the DC resistance or ohms of a particular coil. It determines the inductance in henries of a coil along with “Q”. The number of turns determines how much output the coil will have in relation with the magnetic field and proximity to the strings. Generally the more turns decrease the highend on the pickup. The less turns increase the highend or brightness in a pickup.
F. number of turns per layer
Winding machines that have an automatic traverse control when pre-set for the diameter of the magnet wire determines the pitch of a wind the the threads on a screw. The faster the pitch decreases the turns per layer and the slower the pitch allows more turns per layer. The maximum number of turns side by side of a coil is determined by the overall diameter of the magnet wire including insulation. Winding over the maximum desired number of turns per layer begins to stack and bulge the coil. This usually happens when a pickups is scatter or hand wound. The traverse control automatically travels back and forth at the rate of the pitch setting.
G. number of layers
The number of layers is determined by the number of turns per layer and the total turns of the coil. For example if a coil gets 8,000 turns and there is a 100 turns per layer then there would be 80 layers. The pitch or distance between each layer determines the inductance of a coil.
H. automatic layering
Automatic layering is the same as automatic pitch control and info given under “number of layers per turn”. Automatic means it is done by mechanical means other than scatter or hand winding.
I. scatter winding
Scatter or hand winding is where you guide the magnet wire being wound on the coil back and forth by hand. As the motor speed and direction determines the coil being wound, it will also determine the tension and electrial phasing.
J. tension
Magnet wire being wound and held by mechanical or by hand will determine the tension on the coil. Tension that is too high will stretch the magnet wire and increasing the DC resistance and possible cracking and shorting of the insulation. Winding a coil with too much tension can warp and flair the bobbins.
K. winding direction
The winding direction of a coil determines the phasing electrically when combined with a north or south magnetic field. If two pickups have the same magnetic polarity facing the strings and one coil is wound top coming and the other is wound top going then the two pickups will be electrically out of phase.
4. Pickup placement:
A. distance from bridge or neck
A pickup moved closer to the bridge will sound brighter but will have less output due to less string vibration. Moving the pickup further away from the bridge will sound less bright, fuller and more output. Watch a guitar string and you’ll see the string vibrating more over the neck pickup than the bridge pickup even though the two pickups may be wound identical.
B. distance from strings
The closer the pickup and magnetic field are to the strings the more output the pickup will have. The further away the less output it will have.
5. Pickup circuit:
A. value of volume and tone controls (measure actual values, not value stamped on bottom).
Many volume and tones controls have a value stamped on the bottom such as 250K, 500K, or 1 meg. but actually measuring the pots from the #1 & #3 lug will give you the precise value. Pots used for a volume control that say 265K will make the pickup sound brighter than a pot that has a value of 235K. The manufacturer has an allowable tolerance for his manufacturing specifications. That’s why changing your controls can make your instrument sound different.
B. capacitors for tone circuit
Capacitors can determine how much bass your instrument will have. Make sure they are the proper value and keep to a low voltage like 25V. The standard for guitars and basses is .05 Mfd. 25Volt.
C. gauge of hookup wire
The hookup wire used is important for wiring instruments. Shielded wire works best for maximum reduction of outside interference. Single conductor insulated wire used for Fender style instruments should use 22 AWG stranded. Solid core insulated wire should not be used and harder to work with when making assemblies. Solid core insulated is used in most Fender amplifiers for hard wiring the circuit boards. Using wire that is to thin will increase the DC resistance in the total reading in the pickup and capacitance to the circuit. Wires should be kept at a nominal length when at all possible.
6. String gauge:
A. alloy
Strings are made from spring steel and the wound strings are wrapped with various alloys for tone and tension. Spring steel used is similar to the music wire found in hardware stores before going through the process of putting the ball ends on. Guitar and bass strings usually have a wrapping of various alloys and the string diameter is determined by the diameter of the wrapping which influences the pitch or how close each turns is wrapped. The type of alloy used for the strings will determine the magnetic attraction needed to move the magnetic field from the pickup.
B. diameter
The diameter is determined by the diameter of the bare spring steel and if it’s plated and diameter of the wrapping or surface condition of the string when finished. The larger the diameter of the spring steel or string guage usually increases the output of the pickup.
C. round wound, flat wound, tape wound, half round.
Round Wound strings are tightly wrapped with a round alloy side by side for the duration of the string over an inner core of solid spring steel. The diameter is determined by the diameter of the inner core spring steel plus double the diameter of the wrapping.
Flatwound strings are wound with a flat tape alloy for the duration of the string usually over a previously round wound string that’s also wound around a solid inner core of spring steel.
7. Cables:
A. guitar cords and length.
The length and conductor used in making guitar cords can determine brightness of your instrument. Low capacitance cable the favorite of Eric Johnson allows the high end to be heard with more clarity. The length of the cord too is important to the overall sound of the instrument but it didn’t bother Albert Collins when he used his 100 foot cable to walk into the crowd.
8. wood, finish, hardware
A. type wood, weight and density
The type wood used like Alder, Ash, Maple, Mahogany or other exotic woods play an important factor on the tonal qualities of an instrument. The heavier woods tend to make the pickups sound brighter the lighter woods like Basswood and Alders tend to soften the sound of the instrument and make the pickups sound smoother. The grain of the wood or tightness of the wood will play an important factor in how the pickups react with the wood. My favorite woods are Alder for Strats and swamp ash for Telecasters.
B. finish
The finish used on the instrument will change the sound of your pickups making the body compress the tone and sound of the pickups. The old lacquers and enamels used years ago age and allow the instrument to breath and respond to the total vibration of the instrument. The modern plastic and water base paints don’t do the instrument justice in my opinion cause it mutes the tone of the wood like a capacitor in a tone circuit.
C. hardware
The hardware used on your instrument such as bridge material, plating, construction and other factors can determine the sound of your instrument and pickups. The more mass you use can drastically change the tone of the string vibration and sound picked up by the pickup. Even when using large tremolo’s for that twang can make your instrument sound thin because your not getting the body vibration working with the string. The large tremolo’s act like a radiator diffusing the string vibration. This is only my opinion and that’s why I’ve played a Telecaster all these years.
235. I’m looking for a plastic tubing to insulate wires in my wiring harness. Jeff Hopkins-East Orange, New Jersey
One of my favorite suppliers for plastic tubing is the Markel Corporation-P.O. Box 752-Norristown, PA 19404 (610-272-8960/ 610-270-3138 fax#). They are a great supplier of insulating sleeves. Some of their products are:
FLEXTITE TEFLON TFE-Extruded tubing of DuPont Polytetrafluoroethylene
FLEXTITE TEFLON TFE-250-Extruded and expanded tubing of Dupont Polytetrafluoroethylene
HYGRADE THERMOFLEX 1200-Tightly braided fiberglass sleeving
HYGRADE THERMOFLEX 500- Tightly braided and pigmented fiberglass sleeving
FLEXITE SR-200-Extruded silicone rubber tubing
HYGRADE SR-398-Silicone rubber coated fiberglass sleeving in Grades A, B and C-1
FLEXITE SHRINKDOWN HA-150-Semi-rigid extruded and expanded modified polyvinylidene fluoride
HYGRADE POLYTUBE 463-Acrylic coated fiberglass sleeving in grades A, B and C-1
FLEXITE SHRINKDOWN LM-145-Very flexible extruded and expanded modified polyolefin tubing
HYGRADE VF-Vinyl coated fiberglass sleeving in Grades A, B and C
FLEXITE SHRINKDOWN PO-135 CLEAR-Extruded and expanded polyolefin tubing
FLEXITE SHRINKDOWN PO-135 COLORS-Extruded and expanded polyolefin tubing
FLEXITE HT-105C-Extruded vinyl tubing
FLEXITE SHRINKDOWN HT-105-Extruded and expanded vinyl tubing
FLEXITE H.W. SHRINKDOWN HT-105-Extruded and expanded vinyl tubing
Sleevings are good for doing wiring assemblies that have pickups with exposed braided shield similar to the Gibson humbuckers designed by Seth E. Lover. The sleeving helps keep the bare insulation from hitting contacts on switches and volume and tone controls.
236. I’ve seen lacing and spot tying material for wiring a harness in amplifiers. Where can I find a similar material to lace my pickup harness. Jeff Greene-Liverpool, England
There are several types that can be used. A company called Western Filament, Inc.-4680 San Fernando Road, Glendale, California 91204-1897 (818-247-5880) makes several types of lacing materials:
Type I Nylon lacing tape consists of a flat braided, high tenacity nylon yarn impregnated with wax or other materials to meet industry standards.
Type II Polyester lacing tape consists of a flat braided high tenacity polyester yarn impregnated with appropriate finishes to meet industry specifications.
Type III Teflon lacing tape is flat braided tetrafluorocarbon (teflon) for high temperature applications and resistant to fluids and chemicals.
Type IV Teflon coated fiberglass lacing tape has individual glass fibers coated and braided into a flat tape.
Type V Nomex lacing tape is a high temperature fiber braided into a flat tape and has improved knot holding characteristics.
Type P Nylon lacing twine is round twisted high tenacity nylon impregnated with wax or other finish to meet industry standards.
Mono-Ty is a low cost non-braided, nylon wax impregnated lacing tape for use in commercial industry applications.
Types of lacing and spot tying materials:
Round twisted twines:
Flat braided tapes:
Non-braided flat tapes:
Western Filament can twist, dye and braid yarns for your assembly needs especially for manufacturers.
237. I’m a new guitar player and would like to know how the switches work on some Fender guitars? Johnny Thompson-Dallas, Texas
There are many instruments and custom wiring circuits that determine what combination of pickups can be used. A tone circuit can have active or passive components to enhance the sound of an instrument. Natural enhancement is done by the combination of woods, hardware and amplification. Below are a few common instruments and how the selector switch works with each instrument.
Instrument Lever Switch Position-Pickup Selected
50’s Telecaster: (1) Bridge position-Bridge pickup only.
(non-blend control) (2) Middle position-Neck pickup only.
(3) Neck position-Neck pickup only-full bass from grounded capacitor.
Master volume control for both pickups in all three positions.
50’s Esquire: (1) Bridge position-Bridge pickup-full treble-tone control doesn’t work in this position.
(2) Middle position-Bridge pickup-tone control functional.
(3) Neck position-Lead pickup only-full bass from grounded capacitor.
Master volume control on all three lever switch positions.
Telecaster-Current: (1) Bridge position-Bridge pickup only.
(2) Middle position-Bridge & Neck pickup.
(3) Neck position-Neck pickup only.
Master volume & tone control in all three lever switch positions. Telecaster Thinline: The Telecaster Thinline used a 3 position lever switch.
(1) Bridge position-Bridge pickup only
(2) Middle position-Bridge & Neck pickup.
(3) Neck position-Neck pickup only.
Master volume & tone control in all three lever switch positions. Telecaster Deluxe: The toggle switch was made by Switchcraft and also used by
(inc. 70’s Custom Gibson Guitar Company.
Elite) (1) Down position-Bridge pickup only-individual volume & tone.
(2) Middle position-Bridge & Neck pickup.
(3) Up position-Neck pickup only-individual volume & tone.
Stratocaster: 3 Way: The 3 way switch had to be carefully offset for the 2 & 4 position.
(standard wiring) (1) Bridge position-Bridge pickup only-no individual tone control.
(2) Middle position-Middle pickup only-individual tone control.
(3) Neck position-Neck pickup only-individual tone control.
Master volume control in all three lever switch positions.
Stratocaster: 5 Way: The 5 way switch allowed for instant 2 & 4 position.
(1) Bridge pickup-Bridge pickup only-no individual tone control.
(2) Bridge & Middle position-Bridge & Middle pickups in parallel.
(3) Middle position-Middle pickup only.
(4) Middle & Neck position-Middle & Neck pickups in parallel.
(5) Neck position-Neck pickup only.
Master volume control in all five lever switch positions
Toggle Switch
Duosonic: The Duosonic uses a 3 position toggle switch for pickup selection.
(1) Down position-Bridge pickup only.
(2) Middle position-Bridge & Neck pickup in series.
(3) Up position-Neck pickup only.
Master volume & tone control in all three positions
Jazzmaster: The Jazzmaster has a unique switching system. The single slide switch near the two rollers controls what pickup circuit operates.
When the slide switch is in the down position the toggle switch is operative:
(1) Toggle down position-Bridge pickup only.
(2) Toggle middle position-Bridge & Middle pickups.
(3) Toggle up position-Neck pickup only.
Master volume & tone control for both pickups in this position.
When the slide switch is in the up position:
(1) Neck pickup only-The two rollers are operative for independent master volume & tone control for the neck pickup only.
Jaguar: The Jaguar has a unique switching system similar to the Jazzmaster. The single slide switch near the two rollers controls what pickup circuit operates.
When the slide switch is in the down position the 3 slide switches are operative:
(1) Neck position slide switch turns on & off the neck pickup only.
(2) Middle position slide switch turns on & off the bridge pickup only.
(3) Bridge position slide switch puts a capacitor in the tone circuit and makes the pickups have less bottom.
Master volume & tone for both pickups in this position.
When the slide switch is in the up position:
(1) Neck pickup only-The two rollers are operative for independent master volume & tone control for the neck pickup only.
Jazz Bass: The two pickups are control by two of the three control knobs.
(1) Neck pickup controlled by 1st volume control. (neck position knob)
(2) Bridge pickup controlled by 2nd volume control. (center knob)
The master tone control for both pickups is the 3rd knob.
Precision Bass: The Precision Bass single coil pickup on early models.
Single coil: Single pickup controlled by master volume & tone control.
Dual coil: The dual coil pickup uses a single master & volume control.
Mustang: The Mustang guitar uses 2 - three position slide switches. Each switch has a front or neck position, center or off position and rear or bridge position.
(1) The front slide switch turns the neck pickup on and off. It puts the neck pickup in or out of phase with the bridge pickup.
(2) The rear slide switch turns the bridge pickup on and off. It puts the bridge pickup in or out of phase with the neck pickup.
Switch position: When both slide switches are in the front position, both pickups are in phase with each other. When both switches are in the rear position, again both pickups are in phase with each other. When both slide switches are in opposite positions, both pickups are electrically out of phase with each other.
VI String Bass: The Bass (VI) uses 4 slide switches to control the pickups. 3 slide switches are used to turn each of the 3 pickups on and off. The 4th slide switch is to change the tone of the pickups.
(1) The number one slide switch (closest to the neck) turns the neck pickup on and off.
(2) The second slide switch turns the middle pickup on and off.
(3) The third slide switch turns the bridge pickup on and off.
(4) The fourth slide switch adds a capacitor to the circuit of the 6 String Bass to give a different tone.
The volume and tone are controlled by a two potentiometers.
Jerry Donahue: The Jerry Donahue Telecaster has a unique wiring designed for Jerry’s need and tonal character. It uses a special 4 pole 5 position lever switch.
(1) Neck pickup with tone control out.
(2) Neck pickup with tone control in.
(3) Neck & Bridge pickup with tone control in.
(4) Neck & Bridge pickups-neck pickup phased electrically with capacitor in and with tone control out.
(5) Bridge pickup with tone control in.
Misc. Instruments: Bullet H-1-dual pickup system with push button coil split-master volume & tone control.
Deluxe 6 & 8 Steel-Single neck lap steel-two pickup with blend control and master volume & tone control.
Lead I- Uses two 3-position toggle switches for the two coils in the humbucking style pickup. The Lead I uses one bridge pickup with master volume & tone.
Lead II-3 position toggle switch for neck & bridge pickup-master volume & tone control for both pickups.
Mandolin-master volume and tone control-no selector switch. Musicmaster-Single pickup and master volume & tone control.
Musicmaster Bass-Single pickup and master volume & tone control.
Mustang Bass-master volume and tone control-no selector switch.
Pedal 1000 & 2000-The steel guitar uses a 3 way lever switch for desired pickup and master volume & tone.
Stringmaster Steel-Single neck-two pickup system with blend control to combine second pickup. Master volume and tone control.
Stringmaster Steel-dual neck & triple necks determined by lever switch and output from each neck goes to a master volume and tone control. Each neck has a blend switch for desired tone.
XII String-rotor switch for pickup selection and master volume & tone control.
238. What kind of hook wire is used on the my 70’s Stratocaster? Ken Roth-Buffalo, New York
The early hookup wire used during the 50’s & 60’s is commonly known as cloth braid push back hookup wire. It was saturated in wax and braided with a variety of colors such as natural (white), black, yellow, red, blue etc. The standard wire used on Fender Guitars is 22 gauge, 7 strand and sometimes tinned with solder to add strength and stiffness. The early Fender amplifiers used a solid core hookup wire instead of stranded for hard wiring the circuit boards. After the cloth braid wire was eliminated, a Teflon coated insulation was used in production and Fender continued using the 22 gauge, 7 strand wire that was tinned. The Teflon hookup wire feels stiff and slippery to the touch. It works well when soldering because the insulation doesn’t melt or shrink easily when using hot soldering irons.
239. Does magnet wire used to wind coils just come in round insulated copper? Bill Hawkins-Toronto, Canada
Magnet wire can come in a variety of shapes and sizes. Magnet wire can be twisted with numerous strands, bonded side by side in pairs with the same or different gauges or made square or rectangular. A company called “Molecu Wire Company”-P.O. Box 495A, Farmingdale, New Jersey 07727. Phone 201-938-9473, Fax 201-938-3189 makes custom magnet wire for speakers and special coil applications.
Typical Properties of Metal and Alloy Wires used for electrical conductors:
Silver-Commercially Pure Ag Copper-99.9, Min. Cu
Gold-Commercially Fine Au Cadmium Copper-1 Cd, Bal. Cu
Zirconium Copper-.15 Zr, Bal. Cu 1350 Aluminum-99.5 Min. Al
1100 Aluminum-99.0 Min., Al 5005 Aluminum-.8 Mg, Bal. Al
Beryllium Copper-.19 Be, .20 Ni Min., Bal. Cu
Copper magnet wire is most commonly used in pickup building because of price and availability. Silver and gold magnet wire is very costly as compared to copper magnet wire. A pound of copper 42 gauge magnet wire could cost $25 and a pound of gold would be well over $400.
240. I added a second pickup to my Gibson Melody Maker guitar and when using both pickups together they sound thin. Are they out of phase? Ron Dawson-Glasgow, Scotland
When adding an extra pickup in your guitar two things can happen. The coils can be electrically out of phase or magnetically out of phase. In either case there are a few things you can do to remedy the problem. You can carefully remove the bar magnet in your existing Melody Maker pickup and flip it over 180 degrees. When you look at the bottom of the pickup you will see the bar magnet within a nylon bobbin. The magnet is magnetized across the width or the 1/2 inch dimension, not the length or thickness. The magnet will usually have black lines on the north side of the magnet.. If the black lines can be seen on the exposed side of the magnet, pull the magnet out and flip over and put the black line side of the magnet back into the bobbin. Flipping the magnet over 180 degrees will magnetically reverse the phasing. You can reverse the hookup wires from the pickup that are soldered to ground and to the hot contact. Reversing the two wires will electrically make the two pickups in phase. Reversing the magnet and wiring can be done to the newly added pickup and should be done with extreme care to avoid damage to the coils. Reversing either the magnet or wiring will make the two pickup compatible with each other. Magnets should not be reversed in pickups such as Fender bobbins where the coil is wound directly onto the magnets.
241. What kinds of pickups are most difficult to wind? Tim Conrad-Detroit, Michigan
There are many different types of coils wound directly on magnets, paper bobbins, thin fibre bobbins, and rewinding bobbins that have been distorted from hot wax or shrink with age. Most bobbins can be easily wound if using the proper winding fixtures and proper tooling. Winding coils onto magnets such as Dan Electro pickups are fun to do and use no bobbin and don’t have walls to hold the coil windings. Many old National pickups are made with what looks like old time cards and straws glued together to form the bobbin. The old National pickups use 6 or more bobbins each wound to the desired number of turns and hooked up in series with each other. If one coil fails, the circuit is incomplete and the pickup stops working. Many old Fender Lap Steel pickups have to be rebuilt as many use a plastic celluloid to hold the fibre sides together. Over the years the plastic shrinks and the bobbin can fall apart. Others have cardboard that can deteriorate in time. It is important to make proper holding fixtures when winding so the pickup doesn’t shoot out from the winding mandrel when spinning. You need to use slower winding speeds when winding coil forms that are fragile and can’t withstand extreme winding tension. Slower winding speeds keep the bobbin from distorting and falling apart when winding. Winding at faster speeds adds more tension to the winding and puts much pressure on the bobbin. Always take care when handling or taking pickups apart. Many are fragile and disturbing them can make the pickup in operative. Always move the hardware slowly from the coil forms as the coil can become easily snagged.
242. Where can I find old pickups to experiment with? Roger Crawford-Tampa, Florida
There are many places you can look for old pickups. I’d start with the local music store and ask them if you can look through some junk parts and that your experimenting on some new pickup idea. Many times they have old pickups thrown in a box especially old humbuckers where one of the coil may still be operative. Even broken coils can be fixed with a little care and time given to them. I try to save all coils before rewinding them and you should too. I’ve seen ad’s in newspapers where hobbyist advertise looking for old parts to mess around with. Hanging out with other guitarist is a good place to find odds and ends as most guitarist’s are always working on their instruments. I’ve found lot’s of old guitar parts at garage sales, swap meets, flea markets and once found a 63’ Deluxe Reverb for $50 at a garage sale. There’s lot’s of products out there especially with all the after market products that have been made for years and you can really find out that someone’s junk is another man’s treasure. I always have guitarist’s calling me, saying “guess what I just found”! I used to ask around who the local guitarist’s are and who they took lessons from. Call music teachers and ask them if they know of guitar repairman or players that like experimenting with their sound. After awhile you’ll have many contacts and boxes of neat parts!
243. What is an electric guitar pickup?
A guitar pickup is basically a magnet or magnetized polepiece, a coil wound to the desired impedance that’s connected by hookup wire to a suitable amplifier and speaker. The pickup is a generator that senses the movement of the vibrating ferrous guitar or bass string as it moves through the magnetic field. The pickup can have a variety of pole piece designs and when the string vibrates the movement of the magnetic field produces an alternating current or signal of certain frequency and output. Typically a guitar pickup can consist of 6, 7, 12 or more strings. The pole pieces can consist of magnetic rod pole pieces similar to Fender style pickups, bar magnets such as Gibson Melody Makers and Firebirds, ferrous studs and screw polepieces similar to Gibson traditional humbuckers, laminated blades or solid bars similar to Gretsch pickups and many other combinations of adjustable and permanent, blades and rod pole pieces.
244. What makes a bass pickup?
A bass pickup has similar components as guitar pickups but traditionally had 4 pole pieces as compared to 6 or more on traditional guitars. Now days I’ve seen 3 to 9 strings basses which create a need for modern design pickups. Early Fender single coil Precision Bass pickups had between 8 & 9,000 turns and the split coil Precision Bass had 10,000 turns per coil and wound in opposite directions for a humbucking effect. Jazz Bass pickups where wound under 10,000 turns because they had a longer winding length and if wound to hot the pickups would loose clarity and presence. Early Gibson bass pickups would be wound with 20,000 of 42 gauge plain enamel wire and would sound full but lacked presence. Rickenbacker bass pickups often used a .0047 mfd. capacitor in series with the output to give the pickup presence and less bottom. Fender Precision and Jazz bass pickups usually have two poles per string to keep the output balanced as the string vibrated from side to side.
245. What makes electric guitar pickups different?
a. Magnet type, b. Magnet wire gauge, c. Bobbin shape, d. Number of turns, e. Polepiece type
a. The type of magnet that is used. Ceramic magnets are used for their magnetic strength and generally cost less than cast alnico magnets and ceramic’s are more fragile and can chip and break easily. Cast Alnico rod and bars come in a variety of grades and can be fabricated into rods, bars or many custom shapes. Alnico magnets can be sand molded or sintered under extreme heat and pressure. Alnico magnets are made from sand cast rods to a desired diameter and ground to the desired dimensions to the manufacturers specs. The ceramics are made from a mixture of magnetic compounds and fillers and mixed into a paste, baked into a brittle cake and sliced into the desired dimensions.
b. Magnet wire is insulated to keep the turns from shorting out and the diameter and insulation determine the American Wire Gauge. Magnet wire comes in a variety of diameters and insulated with a variety of insulation’s. The insulation’s can be made with traditional coatings such as Plain Enamel, Formvar, Polyurethane, Nylons and bondable coatings. The magnet wire gauge is named Minimal, Nominal and Maximum. Magnet wire is measured with out insulation and with insulation added. The insulation can come in a variety of thicknesses that add tuffness and durability. Normal magnet wire used for most passive guitar and bass pickups is 42 AWG. The American Wire Gauge is the standard by which all companies measure their products in the USA. When you get into active and low impedance pickups and larger diameter magnet wire can be used to match the coil to the pre-amp or active circuit. There are many ways to make a pickup using the various gauges of magnet wire and extreme care must be taken when you handle magnet wire. Oils and acids from your hands can contaminate some grades of magnet wire and can cause insulation breakdown over a period of time.
c. The bobbin shape is an important factor in the winding area and the tonal character the pickup will have in relationship to the polepiece arrangement. How tall and wide a bobbin is can determine if the pickup sounds thin and bright or fat and full. The spacing of the polepieces is usually determined by the string spacing between the bridge and neck position. Usually the neck pickup has a narrower pole spacing than a wider bridge pickup. For economy most manufactures of pickups use the same pole spacing for both neck and bridge pickups. The position of the coils in relationship to the strings and magnetic field within the bobbin can determine the particular tonal character of a pickup. Many instruments use one, two, three or more single coil pickups for a variety of tones. Humbuckers can be wired several different ways and a combination of positions can give you a multiple of tones. The proximity of the pickup(s) under the string and switch position can alter the tonal variations to ultimate sounds desired by the player. Eric Johnson plays his favorite 54’ Strat, and Albert Collins, Roy Buchanan and James Burton all have their favorite instrument for their particular tone. The shape of the pickup and how it is wound either by hand or machine when combined with wood and hardware give you a distinctive sounding instrument.
d. The number of turns with a particular wire gauge will determine the maximum number of turns that will fit on a particular bobbin. Thinner magnet wire will allow more turns on a specific bobbin than a heavier gauge. If you can only get 8,000 turns of 42 gauge magnet wire on a particular bobbin, you may be able to get 10,000 turns of 43 gauge magnet wire. The number of turns and magnet wire gauge is important to the sound and output of a pickup. Generally the more turns that are added to a coil the pickup will sound louder and fuller. Less turns in a coil will give the pickup less output and brighter sound. The higher the gauge of magnet wire, the wire gets thinner. Along with winding pickups to a number of turns, a pickup can be wound to a desired DC resistance. This can be time consuming unless you are using consistent tension on the magnet wire, exact winding speed as the tension can be increased on the magnet wire with increased speed and less tension with slower speeds. The lubricant on the magnet wire will also determine how the magnet wire layers itself turn after turn. Magnet wire can vary in diameter throughout the spool it is being used to wind from. The de-reelers are important too as they can vary the tension and how tight the coil is being wound. Winding a coil too fast and with too much tension will stretch and can crack the insulation causing turns to short and giving inconsistent DC resistance
e. Polepieces used on guitar and bass pickups can be steel stud polepieces connected to a particular magnet, cylindrical rod magnets, bar magnets, ferrous blades and custom poles. The magnetic path to the vibrating string determines the output and tonal quality of a pickup and the pickup placement between the neck and bridge position will determine the output, fullness and how bright the pickup will sound. Output is also determined by height adjustment, gauge and alloy strings are made of. The diameter of a pole piece and it’s magnetizing ability to magnetize the string is an important factor. The field produced by external magnetic field through the coil or inductor and how the current travels through a coil. The winding direction around the pole pieces can determine electrical polarity and the way the magnets are magnetized determines the magnet polarity. A magnet is in a pickup to magnetize the strings that inturn vibrate and move the magnetic field back and forth through the coil and produce the alternating current. A pole piece can be all South polarity or all North polarity in the same bobbin. If you re-arrange the magnet pattern within the same bobbin the phasing in combination with the coil becomes affected. In humbuckers usually one bobbin is all South and the other bobbin is all North. When both coils are wound in the same direction and the two finishes are hooked together, the beginning of one coil is grounded and the beginning of other coil is positive, and finally each have opposite magnetic fields the pickup the pickup is humbucking-series-in-phase. Reversing the magnet polarity and wiring can make for a pickup with many modifications. This is some interesting to experiment with.
246. Why are covers used on pickups?
Plastic covers are used to protect the coil from damage and to keep the string from snagging the bobbins. They are used cosmetically to enhance the appearance of an instrument and normally do not alter the tone of the instrument. Metal covers used on Humbuckers and Telecaster rhythm pickups are used to reduce unwanted outside electrical interference commonly produced by transformers, light dimmers and bad wiring. Seth Lover used covers on his humbucker to reduce electrical interference and to cosmetically enhance the appearance of the pickup. The plating and cover material can alter the tone of a pickup. Nickel Silver is most commonly used on Gibson style humbuckers because it has less effect on the high end. Some companies use Aluminum and Brass which cut too much of the high end out of a pickup. Many types of plastics are used for injection or thermal formed covers. Some plastics used are High Pressure Styrene’s, ABS and Nylon’s. Several companies used thermal formed covers with the components epoxied inside. Older epoxies can eventually shrink and break the coil in side the cover. Covers are used to help reduce wear and tear to the coils and bobbins and especially keep the picks and fingernails from damaging the coils. Fender Stratocaster pickup covers have 6 holes to allow the magnet rod pole pieces to protrude through. This allows the staggered pole pieces to better balance the output of the various gauge strings. Through the years of playing in hot clubs, sweating and guitar cases with lots of humidity, the bobbin and pole pieces can absorb much moisture and eventually cause the pole piece to rust. Covers with holes in them don’t really help to much. Basically that’s why pickups are dipped in wax to help unwanted vibrations and feedback from loose parts but also to keep the moisture and humidity from being absorbed in the bobbin.
247. What is a volume and tone control?
They are both variable resistors that control the amount of volume or how loud a pickup will be when plugged into an amplifier and the tone control usually rolls the high end off a pickup or combination of pickups. On passive instrument that require no pre-amp or power boost in the circuit the values are usually 250 k audio taper for Fender Strats, Tele’s, P-Bass, J-Bass etc., and Gibson uses 300 k audio taper pots and 500 k audio taper for vintage Gibson’s. Fenders have been known to use 1 Meg. ohm pots on their instruments. On most Fender instruments, solid and knurled split shaft pots are used for volume and tone controls. Fender Stratocaster’s use three knurled split-shaft potentiometers. The knurled shaft keeps the pressure fit knob from spinning beyond 10 on the dial. Telecaster knobs use a tightened set screw to keep it from spinning on the solid shaft. Fender Jazzmaster’s use two nylon Stratocaster volume and tone knobs pressed on to the solid shaft pot and would often become loose with extensive use. Older Gibson knobs are pressure fit on the knurled split-shaft and after time the plastic on the knob shrinks making it difficult to remove or the knob splits and cracks. The contacts inside the potentiometer should be occasionally lubricated with a specific cleaner and lubricator made especially for contacts and pots. Never use WD-40 as some have used and never use oil or grease to lubricate switches as they can cause shorting and a mess inside your instrument.
248. What can be done for loose pickups in a pickguard?
There are a few things I would do, first I’d use a longer or stiffer compression spring , and second if you use a longer rubber grommet (1/4” OD x 1/8” ID x 3/8” long) to take up the loose slack between the mounted pickup and pickguard. You have to remove the old compression spring to replace it with a new one. I don’t like using steel compression springs as they can have an effect or disturb the magnetic field near the pickup. Steel compression springs can vibrate causing feedback and become noisy if loose when hit by a pick. Becareful using a compression spring that are too long because you will have difficulty adjusting the pickup higher if needed. If you use too much pressure trying to adjust the pickup higher, you could accidentally bend or warp the bottom flatwork and in time damage the pickup.
249. I dropped the tone pot in my ES-335 while spraying the contacts. What is a good way to get the pot back in the hole?
The easiest way I’ve found to lift a potentiometer back through the hole is to remove an eraser from a wooden pencil and insert the pencil through the hole where the pot is to be replaced. Carefully push the end of the pencil with eraser removed over the knurled pot shaft and carefully lift it through the mounting hole. Insert the washer and nut on the opposite end of the pencil and carefully slide them down over the shaft.
250. What do I need to do before changing my switches and controls in my instrument?
I’ve been working on guitars for a long time and to this day I still make a schematic drawing of where all the wires go and how the switches and potentiometers are hooked up. I even make a tracing of a pickguard and as I remove the screws and hardware I push the screw in the proper location where they were removed from the instrument. It help keeps the parts from getting lost and it also keeps the different length screws from getting mixed up and put back in the wrong location.
